Ceilometer projector



Dec. 8, 1959 R. E. CROSSLEY 2,916,610

CEILOMETER PROJECTOR Filed July 18, 1957 e Sheets-Sheet 2 a c I 23 -45"40 INVENTOR.

Fawn. 5 Ceasswy BY M f wa Dec. 8, 1959 Ii. .E. cRossL'EY 2,916,610

CEILOMETER PROJECTOR Filed July 18, 1957 6 Sheets-Sheet 4 INVENTOR.

AoYaz. E CEOSSLEY Dec. 8, 1959 Fill ed July 18, 1957 R. E. CROSSL EY2,916,610

CEILOMETER PROJECTOR 6 Sheets-Sheet 5 INVENTOR. 4 0ml. 5. (205545 Dec.8, 1959 R. E. cRossLEY ,6

' CEILOMETER PROJECTOR I Filed July 18, 1957 I e Sheds-sheet e m. us dON F INVENTOR. 20w. 5. CzassLeY BY 0-9. M

iffom y State,

' This invention relates to systems used at airports, and

the'like, in connection with aviation to determine ceiling altitudes. Asis well known to those familiar with theart, these systems are made upof three components, a projector, a receiver, and a computor, whichcomputes data transmittedv to it by the projector and receiver to givean automatic ceiling altitude determination.

Prior to 'this time, mercury arc lamps have been used in 'the projectordue to the fact thatthe projector must project, an" intermittent beamhaving a predetermined frequency; and the receiver responsive only toreflections havingtthe ,same'frequency. Mercury arc lamp's,'howeven/develop a.highudegree of heat and hence suitablecoolingzapparatus; which is both costly. and cumbersome,

has toibe incorporated in the projector. Consequently;

attempts; have, been made ,to .use high intensity incandescentlamps witha 'shutteriarrangement in the projector to g e the desired frequency to.the light beam.. High intensity incandescent lamps,-'howev'er, arelobjectionable because they have a relatively short useful-life duetothe; -hea t developedinthelamp by the concentrated filaments, .1, f m

x,3A ccordingly, it is an object of .this invention to provide aceilometerprojector having an arrangementlof parts.

whereby theuseful life of the ceilomete'r projector/lamp isincreased. 11 ln addition, it is an object of this invention to provide a v new anduseful shutter means for-interrupting ascentinuous beam lamp in aceilometer projector.

The invention consists in the novel features and in the combinationsand.constructions hereinafter. set forth and claimed. '1 H In describingthisinvention, reference is had to the acmp ty gfi awipgsin which, likecharacters designate d i iz din pausin l h oview 1 V 171 hfi w s sr. V

F'gure 1..is an leyation shown, partly in section of. a I i f t ilis myivcn p 1 I E- r 2 is 'a side elevation, s hown partly in sectionandpartly'br'oken'away, of the right-hand side of the projector with thereflector and lamp assembly rotated 90 from that shown in Figure 1.

'-'-'-Fi'gure 3- isa 'view, similar is ri 'urez, "of theleft liand sideof the projector.

Figure 4 is a view, looking to the left, Figure 3, with parts brokenaway and parts in section.

Figure 5 is a view, corresponding to line 55, Figure 1, and shows amodification of the drive for rotating the reflector and lamp assembly.

Figures 6, 7, 8 and 9, are schematic illustrations of the operation ofthe invention. 1

Figure 10 is a schematic illustration showing the wiring diagram of theinvention.

With reference to Figure 1, it will be seen that the projector is madeup of a cabinet 20 on which the projector chassis 21 is mounted, and adome or cover 22, of transparent material, is pivotally mounted on thechassis 21, as at 23. The dome has a section hinged, as at 24,

r. .2 4 so as to provide an acces s'door 25,'which may; to"provide'access torelampthe projector.

With reference now to Figure 4, the chassis 21"ha s an inwardlyextending'flange 28 upon which suitable bear ings 29, 30, are mounted atopposite sides of the chassis, as byfasteners 31. Journalled in theupper, portion of the bearings 29, 30, isya shaft 32. The bearing'29'has adownwardly extending, arm .33 formingfa support for a motor toeifect rotation of the shaft 32. g 1 In the form of theinventionillustrated in Figures 2, 3 and 4, the shaft 32 has a pulley35,aflixedto its lefthand end, and is connected by means of a" belt 36 toa pulley 37' aflixed to a shaft 38 journalled ingthe'be'aring'bracket"29'. A pulley 39 is aflixed to theinner 'end of shaft'38 and isconnected'by' a belt 40 toa pulley" "41 mounted-on thearmature shaft 42of a' s'yiichroriou'smotor 43. Referringnow to the modification shown inFigure 5, the left-hand end of the drive shaft 32'is received in a gearbox 45 whichhas a suitable connection to'a motor, not'shown. Theonly'difle'rence in "the form of the' inventionshown in'Figures 2, 3 and4,and -that'showhin Figure 5, being'the manner in which-the central:

shaft 32 is driven. I Referring now to Figure 4, it will be' s'een that;a I h of dish-shaped'reflector brackets 50, 515'are'fniou'ritd, iii backto back relation on opposite sides of thesha'ftiBZ by fasteners 53 whichextend through bosses'54 formed on'the reflector brackets. Eachreflector bracket premier onuzthe.peripheryz thereof, and at oppositeside's of' -the axis'thereofywith aipair ofbos'ses 5 5. A 'pa'ir ofrods60 are mounted in complemental bos's'es' '55, and apair of'rods 61"aremounted'in the bdsses 55 .at the opposite sides of the brackets 50, 51,the rods '60l, '61] extending out wardly beyond the'brackets50,-51.'

As will be seen from Figures 1', 2 and'4, there are'adit stably mountedon the outer ends 'ofthe arms 61 a pair .of-mounting :plates' 65." 1 Onthe outer 'ends of the arms '60,;se'e Figures, 3 and 4, area-pairof"moun'ti'n'g 1 plates 6ti;:-;As will beseen from Figuresl4 and,"an-adf' justing -plate;70;is mounted orreachofithe plates'66-bymeansof-aiplurality of. threaded studs 7l andnut's72. Afiixedto;eachof 'the plates 70; is an .arm '75 .which "has a goose neck 76 atits-.i nner.-,end;=and. incandescent lamps 77,, 78, -.are-mountdon. thegoose in'ecks' 76. Suitable powercorinections to the'lamps 77, 78,- areprovided but have 'not'been shown 'in these figuresLwDire to the'fac't';

that the plates 70 are adjustably' mounted 'on the plates 66 which, inturn, are adjustably mounted on the arms 60; the lamps maybe adjusted intwo planes to position the l a mpswat the focal point ;of the reflectorscarried by Mounted, on themcuutingplates 65, carried by the i ,5- gP 89,see-- Figure 4, on'which a motor supportinglbracket=;81 is mountedby..nieans of a pluralitykcf hreaded studs fih and nuts. 83. therefor; A

synchronous motor 84 is mounted on the bracket 81 by means of fasteners85. The armature shaft 86 of the motor 84 extends into a bearing 87formed in the outer end of the bracket 81, and a shutter 91 is connectedto the shaft by a pin 89. The shutter, called a chopper, includes acylindrical portion closed at one end by the discoidal portion 88 andopen at its outer end 92. The cylindrical portion 90 has a plurality oflengthwise extending slots 93 formed therein, for a purpose hereinafterdescribed.

As will be seen from Figure 4, the cylindrical portion 90 of thechoppers, or shutters, encircles each of the lamps 77, 78, with thefilaments of the lamps 77, 78,-

fiat-r d by sac et-the a plurality of mounting fingers 95 aflixed to theperiph er) of the brackets fasteners 96 are reflectors 100, 101 (seeFigure 5). The lamp 77 is so positioned to b at the o al P int fteflecor 1, 1. at l; 9 ?mR 78 is positioned at the focal point the reflector100. Al o, t motor bracket "80 is adjustably rnounted on plate. 6 5.inprder that the choppers 87 may be adjusted wheneyerfthe lamps have beenadjusted. I I

" 1 in Figures 1 and 2, the rods 61 have a pair oft switch plates 102,103, mounted thereon between the reflector carrying brackets 50, 51. Apair of mercury switches 110, 111, are adjusta biymounted onthe plate 1an a ik P r of switches 1.2, 1. 3, ar adjustebli m un ed cu, h plate10.3,- Ihs refl ctor lamp .39 r t te by llimi9ffiill a ock ise irec-%2,aul 6thmughlQ-, Q es itc o each t 1.3 swit hes 1 0, [1. 2 re dispos dubs antially itcr ltgthe; axe of th r flsstcrs 100. 10h and. the ll a.to the o i her switch of the pair. t

wsrq s sup ie or, the. lamps 7' 8, hyjleads. 11s. f flsenassts o rush1.17, .118. which bear up concentrically mounted slip rings 119,120, seeFigures 16 3110 The slip nssare carried by uitable supportingmembers 121mounted on a plate 122 fixed to he r flec s: brackets The switches1105111. are connected in series to complete a circuit from' "slip ring120, through wires 1 23, 124, switch 111, switch 1 10,; wireq125, wire126, to lamp 78, through wire 128, tq slip ring 119, The switches 112,113, are connected in the same series arrangement to provide. power fromsliprings 119, 120, to lamp 77. A resistor 130 is connected inshutttwith the pair of switches 110, 111, and

t in like manner a resistor 131 is connected in'shunt with the pair'qfswitches 112, 113. r I

As previously stated, in Figures 6 through 10, the reflector and-lampassembly is rotated in a clockwise direction. With the reflectorassembly in the position shqwn in Figure 6-..that is, with the axes ofthe reflect rs extending horizontally, the switches 112, 113, are sopositioned ontthe plate 103 that the contacts of both fiw lches arebridged by the mercury. Accordingly, power-is supplied to the lamp 77 atfull line voltage and h condition prevails while the reflector and lampasreflector brackets 50, 5 1,'=by

itch f a h P ir is isposed i an ular relation 4 sityi 'Thcbeam otcourse, being intermittent at affequencydetermined 'by the chopper 90.However, after the beam has passed the vertical point, the currentsupplied to the lamp is reduced by the resistor 130. This dimming of thelamp 77 prevails because of the arrangement of the switches 112, 113,until the reflector 101 reaches the position shown in Figure 6, at whichtime both of the mercury switches 112, 113, are closed to apply fullline voltage to the lamp77. Exactly the same situation prevails inregard to lamp 78 mounted at the focal point of the reflector 100.

With this arrangement, the lamps 77, 78, are automatically dimmed duringthe movement of the reflectorlamp assemblythrou'ghout an arcofapproximately.260.

, life ofthe lamps.

sembly is;.rotated througha 90 arc to the position shown in Figure 7.However, upon further rotation of the, assembly through an arc ofrelatively few degrees, the, mercury/of switch 113 moves out of bridgingrelation withcthe contacts of the switch and because the switches ofthis pair are connected in series, the circuit isbrokenthrough theswitches "and is thereafter maintained't-hrough the resistor 130. Itwill be understood by those familiar with ceilometer projectors of thistype that the beam emitted by the projector is employed in determiningthe ceiling height of a cloud during the sweep "of the beam fromhorizontal to vertical position.

During this'sweep of the beam, as illustrated by the diagrammatic views,Figures 6 and 7, the lamp 77 recetved full hne voltage to create a beamof high inten- What I claim is:

. 1. Aceflomcter projector omprising acabinet, a light Projectingassembly rotatably mounted on a chassis carried by, said cabinet, saidassembly including a main shaft mounted for rotation on a horizontalaxis, a reflector mounted on said shaft for rotation therewith in acircular path normal to the axis ofrevolution ofthe shaft, a lamppositioned at the focal point of said reflector, said lamp mounted forrotation in. said circular path with said reflector, an aperturedcylindrical chopper mounted on said assembly for rotation in saidcircular pathwith said reflector and said lamp, said chopper encirclingsaid lamp in telescopicflfashion and means for rotating said chopper ata constant speed whereby to give .a predeterminedfrequency to the beamprojected from said lamp and reflector, switch means mounted forrotation in said circular path with said assembly, said switch meansbeing operable to dim said lamp during approximately three-quarters ofeach revolution of said lamp, in said circular path.

2. A eeilometer projector as? set forth in'claim 1, wherein said switchmeans comprises a pair of mercury switches connected in series with eachother and in shunt with a resistor, said resistor being connected inseries with said lamp and a power source, said mercury switches beingdisposed approximately normal to each other so as to shunt said resistorduring approximately one quarter of each revolution of said assembly insaid circular path whereby the lamp is dimmed during the remainder ofeach revolution.

References Cited in the file of this patent Heugal Nov. 5, 1957 FOREIGNPATENTS 136,677 Great Britain Dec. 24, 1919

